Oscillation generator



Oct. 10, 1933. c A, c Lv 1,930,458

oscILLATIoN GENERATOR Filed Oct. 20, 1930 Confal'nrh mercury r4001 0; 40531411 hlly 0.0001 mm prziJllre @UQQQQ/ Charles A. Cal 781'.

ATTORN EY Patented Oct. 10, 1933 UNITED res ears-r f tries 4 Claims.

My invention pertains in general to systems for producing sustained oscillations and specifically relates to such a system in which an oscillatory arc is produced between electrodes in a mercury vapor atmosphere.

One of the objects of my invention consists in producing an oscillation generator employing a two-electrode mercury vapor tube in conjunction with a non-feedback resonant circuit.

Another object of my invention consists in providing an oscillation generator in which means are provided to produce an oscillatory are between a hot and cold electrode in a mercury vapor atmosphere whereby sustained oscillations are set up in a resonant circuit having inductance and capacitance.

A further object of my invention comprises producing an electrical organization having a twoelectrode mercury vapor tube connected in series with a resonant circuit and means adapted to heat one of the electrodes of the tube whereby sustained oscillations are produced.

These and other objects I accomplish in a novel oscillation generator in which changes in potential between a hot and cold electrode in a mercury vapor atmosphere, in association with changes in potential between the plates of an electrostatic condenser, produce sustained oscillations.

In the drawing which accompanies and forms a part or" this specification and in which like reference numerals designate corresponding parts throughout Fig. 1 is a diagrammatic representation of one embodiment of the oscillation generator of my invention; and

Fig. 2 is an alternative arrangement of the embodiment of Fig. 1.

My invention contemplates providing an envelope having an attenuated mercury vapor atmosphere and within which a hot filament and a cold plate electrode are positioned. A resonant circuit having inductance and capacitance is connected in series with these electrodes and a source of E. M. F. is provided to produce an ionization discharge between the electrodes in the mercury vapor atmosphere.

Referring to the drawing in detail, and par ticularly to Fig. 1, an envelope 1 is provided with a plate electrode 2 and a filament 3. The envelope 1 has an attenuated atmosphere of mercury vapor at a pressure of approximately 0.0001 mm., which I have found, in experiments, to be necessary for the generation of oscillations in accordance with my invention. A battery 4 is connected to the filament 3 to heat the same to the proper operating temperature. A resonant circuit having a variable capacitance 5 and inductance 6 is connected in series with the plate 2 and filament 3. A battery 'I is also connected in series with the plate 2 and filament 3 and serves as a source of voltage for the plate 2. The output inductance 9 is electro-magnetically coupled to the inductance 6 and is indicative of a work circuit for utilization of the oscillations 6 produced in the resonant circuit 5-6.

The operation of my system issornewhat similar to that of a carbon arc oscillator. I have found, by experiments, that when the pressure of the mercury vapor within the envelope 1 is of .70 the order of 0.0001 mm., and when the filament 3 is heated to the proper temperature, that vigorous sustained oscillations are produced in the resonant circuit 5-6 if a voltage of a proper value is applied to the plate 2. My experiments have shown that an anode potential of the order of 35 volts, with respect to the filament, produces oscillations of the order of 300 kilocycles per second.

Fig. 2 illustrates an alternative arrangement of the circuit of Fig. 1. It will be seen that here the battery 'I is provided in series with the resonant circuit 5 -6 instead of being in parallel with the same as in Fig. 1. A fixed condenser 8 is provided in parallel with the battery '7 to by-pass high frequency oscillations. The operation of my oscillation generator, according to either Fig.

2 and Fig. 1, is substantially the same.

One advantage of my system resides in the fact that a comparatively low anode voltage is re- .90 quired to produce satisfactory oscillations. Other advantages reside in the extreme simplicity of the electrical organization, it being obvious that back-coupling and other more complicated circuit arrangements are entirely avoided. Although I have shown a preferred embodiment of my oscillation generator it will, of course, be understood that changes will readily occur to those skilled in the art but which will not depart from the intended scope of my invention. I do not, .100 therefore, desire to limit myself to the foregoing except insofar as may be pointed out in the appended claims.

What I claim as new. and original and desire to secure by Letters Patent of the United States is:

v1. An oscillation generator comprising, an envelope containing a mercury vapor atmosphere of substantially 0.0001 mm. pressure, an anode and cathode contained within said envelope, a.ll0

of current connected to said electrodes, and a resonant circuit having inductance and capacitance, said resonant circuit being connected to said electrodes. .7

3. An oscillation generator comprising, an errvelope containing a mercury vapor atmosphere of substantially 0.0001 mm. pressure, a filament and plate electrode positioned within said envelope, a source of current for said filament, a source of current for said plate, and a resonant circuit having inductance and capacitance, said circuit being connected in series with said plate and filament.

4. An oscillation generator comprising, an envelope containing a mercury vapor atmosphere of substantially 0.0001 mm. pressure, a filament and plate electrode positioned within said envelope, a source of plate voltage in series with said plate and filament, a source of current for said filament, and a resonant circuit having inductance and capacitance, said resonant circuit being connected in series with said plate and filament.

CHARLES A. CULVER. 

